Synthesis and characterization of SO42- loaded mixed oxides heterogeneous catalyst: Application in biolubricant

Abstract

A number of SO42- loaded mixed oxides heterogeneous catalysts were prepared by co-precipitation method and sol gel method and their catalytic activities were explored for esterification of fatty acids. The physico-chemical properties of the catalysts were evaluated by powder XRD, TGA, SEM-EDS and Mapping, FT-IR and FT-NMR studies. The prepared catalyst was successfully employed for the esterification of fatty acids. Out of the prepared catalysts, Si-Zr/SO42- catalyst has shown 97 % conversion of fatty acid into fatty acid methyl ester (FAME). Various techniques like 1H-NMR, 13C-NMR and FT-IR were employed to characterize the FAME obtained during the esterification reaction. The optimized reaction conditions for esterification reaction are 7 wt% catalyst (with respect to Oleic acid), 65 ºC reaction temperature, 12:1 methanol to oleic acid molar ratio, and 2.5 hours of reaction duration.